Field of Invention
The present invention relates to an electrostatic discharge (ESD) protection circuit and an integrated circuit, which are applied to the high-speed circuit.
Related Art
Electrostatic discharge (ESD) is a major factor relating to the reliability of electronic devices. A proper ESD protection circuit is necessary for protecting the electronic device from damage by electrostatic.
In a general input/output circuit, the diode is configured for providing the needed ESD protection circuit. For example, the integrated circuit usually has two diodes configured as the ESD element. One diode is connected between the signal pad and a high voltage terminal VDD, and the other diode is connected between the signal pad and a low voltage terminal VSS. When an electrostatic pulse is incurred, the diode is triggered and conducted to discharge the ESD current. Accordingly, the diodes can protect the internal circuit of the integrated circuit from the damage of the electrostatic pulse.
Although the diodes have good ESD protection ability, it may generate parasitic capacitance due to its P-N junction structure. Unfortunately, the parasitic capacitance can seriously interfere the signal transmission and thus affect the performance of the integrated circuit.
Therefore, it is an important subject to provide a protection circuit having high ESD durability without affecting signal transmission.